Start/Update During Editor

I have a MonoBehaviour object, and I would like find if there is a Start/Update for the object that can run while viewing/editing the object in the editor?

ExecuteInEditMode Check that page out for making scripts use Update in edit mode

Could you please add more clarity to the question. All objects will have a Start() and Update() function attached to it. You can press Play button (Ctrl+P) to check it out. However, if you edit the Object in Play/Game mode in Editor, it will revert back to its original properties once you stop the Game.